Induction-coil.



A. K. KELLER.

INDUGTION COIL. APPLIOATION FILED 111111.11998.

'Patented "July 6, 1909. a SHEBTSTSHEET 1.

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A.`K. KELLER.

INDUCTION COIL. APPLIUATION FILED AUG. s, 1908.

Patented July 6, 1909,

3 SHEETS-SHEET 2.

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A. K. KELLER. INDUGTION 00H..

APPLICATION FILED AUG. 3, El908. 927,41 3 Patented July 6, 1909,

3 SHEETS-SHEET 3.

UNITED STATES PATENT OFFICE.

ALBERT K. KELLER, OF LA FAYETTE, INDIANA, ASSIGNOR TO STERLING ELECTRIC COM- PANY, OF LA FAYETTE, INDIANA, A CORPORATION OF INDIANA.

INDUCTION-COIL.

Patented J'uly 6, 1909.

Original application filed September 9, 1907, Serial No. 392,024. Divided and this application iled August 3,

To all whom it may concern:

Be it known that I, ALBERT K. KELLER, a citizen of the United States, residing at La Fayette, in the county of Tippecanoe and State of Indiana, have invented certain new and useful Improvements in Induction-Coils, of which the following is a specification, reference being had therein to the accompanying drawing.

My invention relates to telephones, and particularly to the induction coils used therein and therewith.

It has for its object to provide a set which shall be simple and economical in design, easily assembled, and with the induction coil readily removed from the other parts.

A corollary object is to dispense with cords or circuit wires connecting the detachable induction coil with other units or parts of the complete organization.

The present application is a division of my prior application, Serial No. 392,024, filed September 9, 1907, and is directed particularly to the structure and connections of the detachable induction coil. In order to convey a full and adequate idea of the invention involved therein, however, I shall illustrate and describe herewith a complete desk set especially designed for the purposes stated.

In attaining my object I provide a skele ton standard with a bell-shaped base, the standard being cut away at the sides and having the switch hook springs mounted vertically within it. A double transmitter sup orting head isI fitted at the upper head of t e standard, with a spring jack connection for the transmitter circuit, and the special induction coil, complete in itself, is fitted in the base, and adapted to make connection with the instrument circuits by means of a double spring jack. The openings in the standard are covered, and a suitable grip is provided by means of a tubular sleeve of hard rubber or other suitable insulating material which is held between the base and a retaining ring at the top. The base has an opening of sullicient diameter to permit of the insertion and removal of the induction coil without affecting any of the other parts, and this opening is normally closed by means of a readily detachable cover,

Serial No. 446,732.

Subsidiary features of the invention will sufficiently appear from the detailed de scription and claims hereinafter presented.

My invention is illustrated in the accompanying drawings wherein- Figure 1 is a perspective view of a desk set embodying the same. Fig. 2 is a longitudinal section thereof. Fig. 3 is a detail section of the standard taken at right angles to the section of Fig. 2. Fig. 4 is a detail perspective view of the standard with the insulating shell removed. Fig. 5 is a vertical sectional view of the induction coil and its terminals, detached. Fig. 6 is a top plan view thereof. Fig. 7 is an elevation of the same.

Referring to the drawings, 1 represents the base, and 2 the standard., which are joined together so as to form an integral structure, the standard projecting up from the base and comprising a hollow cylindrical member, cut away on both sides, as shown in Fig. 4, to give access to the switch mechanism as hereinafter described. This standard is preferably stamped out of a flat sheet of metal and then bent into tubular form with its opposite edges adjacent each other and. slightly separated so as to exert an outward spring pressure upon the tubular insulating sleeve 3 which surrounds the standard when the instrument is assembled.. In the stamping operation lugs 4 are formed which project inwardly and toward similar lugs 5 on the opposite side of the opening and secured to these lugs within the standard is the switch mounting plate 6 having the inwardly-projecting support 7 upon which the switch springs are mounted, being insulated therefrom and from each other by the strips of insulating material 8. The terminals of these springs I shall designate as 9, 10, 11, 12 and 13, all of which project down below the support 7 and the insulating strips 8 and form one pair of elements, or the sockets of a double jack-knife switch, the opposite pair of elements or the blades being formed by the terminals 14, 15, 16, 17, of the induction coil I.

The base 1 has a bell-like formation with its upper portion adjacent the apex merging into a neck in which the standard is secured in any suitable manner. This formation permits the induction coil I to be inserted in the base and to have its terminal head 18 project into and it the standard 2. The terminall binding posts 19 of the induction coil are secured to the large lower spool head 20 and connect with the terminal clips 21 on the upper side thereof. Projecting above the upper spool head 22 and supported thereon is the induction coil terminal head 18. This head 18 is provided with a slot 23 which is engaged by a guiding and clamping screw 24 passing through the neck of the base and through the standard 2. The head itself is best illustrated in Figs. 5, 6 and 7. In addition to the slot 23, it has parallel side slots 48 and 49, separated by a central web 50, to which the terminal contacts 14, 15, 16, 17 are secured by means of the transverse bolt 51. The upper end of the head is covered by a retaining plate or ring 52 secured in place by a central screw 53 tapped into the web 50. This web may be integral with the head 22 of the spool. The retaining ring 52 is provided with short slots at 54 and 55, best shown in Fig. 6, overlying the ends of the slots 48 and 49. Through these pass the terminals 14, 15, 16,

- 17, which are therefore held in position and maintained in alinement by the plate or ring 52. The leading in wires from the receiver and from the line pass through a bushed opening 25 on the base and are connected to the terminals 19.

Around the lower edge of the base I insert a leather gasket 26 which is held in place by screws 27, passing through the base and gasket and threaded into a supporting ring 28, which is centrally apertured to receive the cover 29. I form an annular shoulder 30 in the ring 28 to receive the cover 29 and notch the shoulder at suitable points to allow a locking bar 31 to pass. By inserting a Spanner in the openings 32 I am enabled to lock the cover in position or to register the ends of the bar with the notches in the shoulder and thereby release the cover so that access may be had to the induction coil.

Removably mounted in the upper end of the standard and secured therein by means of a screw 33 is the transmitter sup orting head 34, bifurcated at its upper en to receive the supporting lug 35 which is adapted to be held frictionally within the bifurcated` end by the screw 36. The head is also provided with a pair of depending lugs 37 between which is pivoted the bell-crank hook lever 38 in such a manner as to have its lower end impinge upon the switch spring 9. The lower end 39 of the hook lever is provided with an insulating roller to engage the spring, and the spring 9 is bent back upon itself at its upper end to form a good bearing surface for t e roller and at the same time to place its terminal contact adjacent the spring 13 so that a slight movement of the hook lever is sufficient to make or break contact between the two. The switch spring 9 is made heavy so that it will normally force the outer end of the hook lever to rise.

Secured to the mounting plate 6 and insulated therefrom is a terminal contact member 40 which projects above the plate and engages a depending contact member or wiper 41 projecting down but insulated from the depending lugs 37. From this last terminal 41 I pass a wire through the channels 42 and 43 to the hollow transmitting lug 35 and thence to one terminal of the transmitter.

To the back of the mounting late 6 I secure a limiting stop of the insu ating mate rial which is provided with two or more projecting lugs 44 to engage and limit the movement of the contact springs. As illustrated in Fig. 2, only one of these lugs is employed, but where I use the instrument for local battery work it is necessary to use more springs and therefore to provide more limiting lugs. I desire to assemble all instruments alike with the exception of their contact springs, and to change these as occasion may require, adding more contact springs or removing certain of them, as is necessary.

In assembling the instrument, the contact springs are all secured upon the supporting member 7 of the mounting plate and the mounting plate is attached to the lugs 4 and 5. At this time the contact member 40 is secured to the mounting plate and one of the screws which holds it in position passes through the mounting plate, and engages one end of the member having the limiting stops. The other end of this member is attached in a similar manner by one of the screws which pass through the upper lug 4. After the mounting plate has been assembled as a unit and attached within the standard, the insulating sleeve is slipped over the same and the transmitter supporting head is then put in and secured in position by the screw 33 which passes through the limiting ring 45, the standard 2, and into the supporting head. The limiting ring 45 acts to hold the sleeve 3 in position and at the same time to limit the upward movement of the hook lever. This ring is slotted at 46 to register with a similar slot 47 in the standard and all parts are so made that they may be interchanged so as to facilitate and cheapen the cost of any necessary repairs which may have to be made.

Many modifications may be resorted to in practice and changes in the circuit arrangements without departing from the spirit or scope of the invention. Such changes will readily suggest themselves to those versed in the art, and I wish it understood that they are to be considered within the scope and purview of the appended claims.

I-Iaving thus described my invention what I claim and desire to secure by Letters Patent is- 1. A detachable induction coil for telephone desk sets com rising a core with windings thereon, a spoo head of larger diameter than the windings, circuit terminals mounted upon said head outside of the windings, a second spool head, and axially projecting con necting means thereon ada ted to be engaged by instrument termina s when the coil is in position.

2. A detachable induction coil for telephone desk sets comprising a core and windings thereon, a spool head of larger diameter than the windings, binding posts on one side of said head and terminal clips on the other side thereof connected to said posts, a second spool head, and instrument terminals carried upolp an insulated mounting associated there- Wit 3. An induction coil for telephone desk sets comprising a core and windings thereon, a terminal head projecting above said core and windings, and instrument terminals secured to the head and forming one element of a spring jack switch.

4. An induction coil for telephone desk sets comprising a core and windings thereon, an enlarged spool head, line terminals connected thereto, an instrument terminal head projecting above the core and windings, and instrument terminals secured to said head and projecting thereabove and forming -one element of a spring j ack switch.

5. An induction coil for telephone desk sets having an insulating terminal head slotted at its sides, and instrument terminals secured within the slots and projecting above said head and forming one element of a spring jack switch.

6. An induction coil for telephone desk sets having an instrument terminal head provided with side slots forming a substantially central web, instrument terminals disposed Within said slots and abutting said web, and a single bolt passing through the wleb and the terminals for securing them in ace.

p 7. An induction coil for telephone desk sets having an instrument terminal head projecting above the coil and provided with side slots, instrument terminals secured within the slots and projecting above the head, a retaining ring engaging said terminals, and means to secure the retaining ring to the head.

8. An induction coil for telephone desk sets having a slotted terminal head of insulating material projecting above the coil, instrument terminals secured within the slots, a slotted retaining ring engaging said terminals to prevent their displacement, and a screw passing through the retaining ring and threaded into the head for holding the ring in position. Y

9. A detachable induction coil for telephone desk sets having iXed instrument terminals, comprising a core and windings thereon, circuit terminals for effecting outside connections arranged on one spoolzhead, and instrument terminals associated with the other spool head and arranged to engage the fixed instrument terminals when the coil is placed in position.

ln testimony whereoil I ai'liX my signature in presence of two Witnesses.

ALBERT K. KELLER.

litnesses:

GEORGE W. METCALFE, W. E. DooLirrLn. 

